جستجوی مقالات مرتبط با کلیدواژه « Optimal Placement » در نشریات گروه « مکانیک »

This paper aims to use H2 and H∞ norms to optimally place sensor/actuator patches on a flexible structure. Unlike most existing optimization methods, the proposed approach not only increases the norms of the controlled modes of the system but also it can reduce the system's spillover problems by taking into account the residual modes and reducing systems H2 and H∞ norms. The residual vibration of the system is captured considering sandwich structures and the finite element analysis. In order to show the optimal placement effect of piezoelectric patches, the vibrational behavior of the closed-loop system is controlled using strain rate feedback controller. Numerical simulation is performed to study the debonding effects between the sandwich layers.

The subject of this study was vibration damping of Timoshenko beam based on finding optimal place and number of piezoelectric sensor and actuator using LQR controller and MOPSO algorithm. Today, researchers make a lot of effort to make a structure have optimized reliable life, manufacturing cost, and power consumption. One of the researches on optimized and controlled smart structure is through using piezoelectric sensor and actuator so that the sensor and actuator can adopt the best controlling interest based on the type of approach to design the controller upon receipt of a vibration by sensor and with the transfer of vibration signals to the controller. Then, it can transfer a proper signal to the actuator. In fact, it is the actuator that tries to neutralize the vibrations of the structure in order to have a structure with longer life and lower failure and can meet the designer's objective in the best way. In this study, using MOPSO algorithm and defining the design variables, the best number and location to place the piezoelectric sensor and actuator at the bottom and top the bottom and top cantilever beam in in a specified range can be searched and then an optimal model of smart structure was suggested.

Reducing energy consumption is the main purpose of design. Naturally, energy loss in each system can compromise the future of a system. This has drawn attention of researchers all around the world. Contentious structures the same as an engineering structure such as beam, plate, and shell are widely used in various industries. Much of industrial systems include these structures. However, the most important point in designing such structures is to avoid failure, reduce maintenance cost, and increase life of the structure. These points directly and indirectly can describe energy consumption and necessarily cannot meet the objectives of the design and not reach an optimal output and product. Vibration of any continuous system can have poor consequences on performance and can weaken the design of a system. Therefore, the effort to reduce vibration and control the mechanical phenomenon has a significant impact on reduced energy waste of a continuous structure (kinematic energy- potential energy). This paper sought to report scientific and research activities from 1980 to 2013 on vibration suppression of continuous systems focusing on optimal placement approach on the structure and installing piezoelectric S/A and smart model built by control approaches in order to attenuate and control unwanted vibrations of the system against external stimulations and disturbance.